nginx/1.13.9 + njs/head build : ngx_http_js_module.so: undefined symbol

[PGNet Dev]

Upgrading nginx 1.13.8 -> 1.13.9 with usual

	./configure \
	... \
	--add-dynamic-module=/usr/local/src/njs/nginx

and

	cd /usr/local/src/njs/nginx
	hg log | head
		changeset:   450:757271547b56
		tag:         tip
		user:        Dmitry Volyntsev <xeioex at nginx.com>
		date:        Tue Feb 20 19:12:55 2018 +0300
		summary:     Fixed the names of global functions in backtraces.

	ls -al /usr/local/src/njs/nginx
		total 76K
		drwxr-xr-x 2 root root 4.0K Feb 20 11:31 ./
		drwxr-xr-x 6 root root 4.0K Feb 20 11:31 ../
		-rw-r--r-- 1 root root  749 Feb 20 11:31 config
		-rw-r--r-- 1 root root  260 Feb 20 11:31 config.make
		-rw-r--r-- 1 root root  32K Feb 20 11:31 ngx_http_js_module.c
		-rw-r--r-- 1 root root  26K Feb 20 11:31 ngx_stream_js_module.c

No errors on build, but on conf check

	/usr/local/sbin/nginx -t -c /usr/local/etc/nginx/nginx.conf
		nginx: [emerg] dlopen() "/usr/local/nginx-modules/ngx_http_js_module.so" failed (/usr/local/nginx-modules/ngx_http_js_module.so: undefined symbol: njs_vm_value_to_ext_string) in /usr/local/etc/nginx/nginx.conf:34
		nginx: configuration file /usr/local/etc/nginx/nginx.conf test failed

where, line 34's

	load_module /usr/local/nginx-modules/ngx_http_js_module.so;

and

	ls -al /usr/local/nginx-modules/ngx_http_js_module.so
		-rwxr-xr-x 1 root root 1.3M Feb 20 11:26 /usr/local/nginx-modules/ngx_http_js_module.so*
	ldd /usr/local/nginx-modules/ngx_http_js_module.so
        linux-vdso.so.1 (0x00007ffef8db5000)
        libssl.so.1.1 => /usr/local/openssl11/lib64/libssl.so.1.1 (0x00007f8822d18000)
        libcrypto.so.1.1 => /usr/local/openssl11/lib64/libcrypto.so.1.1 (0x00007f882286e000)
        libdl.so.2 => /lib64/libdl.so.2 (0x00007f882266a000)
        libz.so.1 => /lib64/libz.so.1 (0x00007f8822453000)
        libpcre.so.1 => /usr/local/lib64/libpcre.so.1 (0x00007f88221dc000)
        libpcrecpp.so.0 => /usr/local/lib64/libpcrecpp.so.0 (0x00007f8821fd2000)
        libm.so.6 => /lib64/libm.so.6 (0x00007f8821cd5000)
        libc.so.6 => /lib64/libc.so.6 (0x00007f8821934000)
        libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f8821717000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f88231d7000)
        libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00007f8821390000)
        libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f8821179000)

	nm /usr/local/nginx-modules/ngx_http_js_module.so | grep "U njs"
		U njs_vm_external_create
		U njs_vm_external_prototype
		U njs_vm_retval_to_ext_string
		U njs_vm_value_to_ext_string